The main focus of my research is condensed matter theory.
A second area of interest is theoretical particle astrophysics
and cosmology. In condensed matter physics my main interests
are quantum many body physics and quantum effects in disordered
materials. In particle astrophysics and cosmology I am interested
in how high energy phenomena shaped the early Universe, the cosmic
microwave background as a probe of the early universe and
in non-perturbative phenomena in quantum field theory.

Representative past work in condensed matter theory includes
the prediction that quantum interference would make the conductance
of semiconductor rings oscillate in response to electric fields due
to their coupling to the electron spin ("Aharonov-Casher effect") [1].
This prediction was recently verified experimentally. Similarly
my collaborators and I predicted that quantum interference effects
can be used to probe the roughness of the semiconductor-oxide
interface in silicon MOSFETs, the fundamental building blocks of
semiconductor electronics [2]. I have applied methods of supersymmetric
quantum field theory to understand the propagation of electrons in
semiconductors under conditions of broken time reversal symmetry
(for example under the conditions of the quantum Hall effect) [3].
A remarkable experimental development of the past two decades
is the ability to engineer quantum dots - small electronic devices that are
essentially large artificial atoms. I have studied the stability of
electronic matter in these devices. Their physics is controlled by
the interplay of chaotic electronic motion and electron-electron
interaction [4].

My recent work on cosmology is focussed on the observable consequences
of a phase transition in the early Universe on the grand unification
energy scale. We have predicted that such a transition will produce
gravitational radiation that may produce an observable imprint on
the cosmic microwave background [5].

Other interests that are more difficult to classify (art history,
the history of physics) are represented by publications [6] and [7] in
the list of representative publications.